diff --git a/module2/ressources/emacs_orgmode.org b/module2/ressources/emacs_orgmode.org
index d051fe9d1cbc6419f31e9b8df50bcb10f8c6952b..2bccc797efb1dea0caa35f911d8f1a0ee4366d12 100644
--- a/module2/ressources/emacs_orgmode.org
+++ b/module2/ressources/emacs_orgmode.org
@@ -90,8 +90,12 @@ which is now deprecated.
 
 The Web site https://emacsformacosx.com/ proposes precompiled Emacs versions for macOS. Download the latest version (the one that figures prominently on the page) and install it like you would install any other macOS application, by copying =Emacs.app= from the downloaded disk image to a convenient location on your computer.
 
-In case you need to run Emacs from the command line (note: this is not required for the MOOC), you have to enter the full path to the executable. Assuming that you have copied =Emacs.app= to =/path/to/emacs=, this is =/path/to/emacs/Emacs.app/Contents/MacOS/Emacs=. If you just type =emacs=, you will use the prehistoric command-line-only version at =/usr/bin/emacs= provided by Apple.
+If you like working in a terminal (the =Terminal.app= from macOS, or an enhanced one such as [[https://iterm2.com/][iTerm2]]), the standard macOS way of opening a file in Emacs is =open -a Emacs.app /path/to/my/file.txt=. This will launch Emacs, unless it is already running, and then ask Emacs to open the file. Note that this is different from the Unix/Linux way of running Emacs, which is what you see in the videos. Under Linux, you type "emacs /path/to/my/file.txt" in the terminal, which always starts a fresh copy of Emacs.
 
+*** Advanced topics - not required for following the MOOC
+For advanced uses of Emacs, such as calling Emacs from a Makefile to automate document processing, you have to adopt the Unix way also under macOS, because this is the only way to provide parameters other than filenames. However, you have to enter the full path to the executable. Assuming that you have copied =Emacs.app= to =/path/to/emacs=, this is =/path/to/emacs/Emacs.app/Contents/MacOS/Emacs=. If you just type =emacs=, you will use the prehistoric command-line-only version at =/usr/bin/emacs= provided by Apple. You can of course make the Emacs executable more easily accessible using a shell alias, or by putting =/path/to/emacs/Emacs.app/Contents/MacOS/= on your =$PATH=. See the [[https://www.gnu.org/software/bash/manual/bashref.html][bash manual]] for details and explanation.
+
+Be aware that running Emacs the Unix way implies some subtle differences compared to running Emacs the macOS way. In particular, Emacs will inherit the shell's environment variables when run the Unix way, but the user session's environment variables when run the macOS way.
 ** Windows
 Download the [[https://ftp.gnu.org/gnu/emacs/windows/emacs-26/emacs-26.1-i686.zip][precompiled Emacs 26.1]] and unzip the zip file preserving the directory structure, and run =bin\runemacs.exe=.